For purposes of this invention, a pleated shade shall be defined as a shade, blind, screen, curtain, or other similar member for covering an opening which, when in its closed condition to expose the opening, stacks generally along predetermined creases or lines and which, when in its open condition to cover the opening, opens each pleat to only a predetermined extent so that the pleat is maintained. Pleated shades are generally formed from a web-type material which retains its folds, for example impregnated textile fabric, paper or board type material, metalized textile material, etc. Other materials may also be used such as plastics and metals. Such shades are for example shown in U.S. Pat. No. 3,946,788 entitled "Foldable Curtain Screen or Blind Construction and a Method for Producing a Curtain Blind Construction" which issued March 30, 1976 to Hendrik van Muyen. Other forms of pleated shades include, but are not limited to, the various honeycomb and other shade configurations shown in co-pending application Ser. No. 030,167 entitled "Shade and Method for the Manufacture Thereof", filed March 25, 1987. While most pleated shades open and close in the vertical direction, pleated shades may also be oriented to open and close horizontally. Shades of this type are shown in co-pending application Ser. No. 788,460 entitled "Vertical Drape System" filed Oct. 17, 1985, and various continuations thereof.
One problem in pleated shades, particularly long heavy pleated shades, is that the weight of the shade when the shade is in its open position, covering the opening, causes the pleats in the shade, particularly the pleats in the upper portion of the shade, to be stretched. In some instances the stretching is sufficient so that the pleat disappears and the shade hangs straight. The stretching of the pleats in this manner is disadvantageous for at least two reasons. First, the pleats being stretched unevenly over the length of the shade, and in some instances disappearing, is aesthetically unacceptable in most applications where pleated shades are utilized. Second, the stretched pleats may not stack properly when the shade is closed. This is particularly true for shades which may be subjected to wind, jostling or other external forces which may crease or even break the fabric if it is in a substantially flattened condition. Properly pleated fabric is far more resistant to damage from such forces.
To maintain a substantially uniform stretching of the pleats in relatively long shades and in other selected situations, it has been the practice to attach a middle rail to the shade at a selected point between the headrail and the bottomrail and to attach one or more spacer straps between the headrail and middlerail. These straps, which are of a predetermined length, control the spacing between the headrail and middlerail, and thus the extent to which the pleats in the upper portion of the shade above the middlerail may be extended. For very long shades, two or more middlerails may be utilized with spacer straps connected between successive middlerails to control the spacing therebetween and to thus assure substantially uniform extension of the pleats over the length of the shade. In some applications, one or more spacers may also be connected between the bottomrail and the headrail or a middlerail.
With standard spacers of the type described above, the length of the material between rails may still be sufficient such that the pleats do not extend uniformly between the rails, resulting in the aesthetic and other problems indicated above. A need therefore exists for a spacer device which, in addition to controlling the spacing between end bars or rails, is also adapted to provide additional support to the pleats of a pleated shade to further maintain uniform extension of the pleats.
As previously indicated, pleated shades may also be hung so as to open and close horizontally rather than vertically. For such shades, there is also a problem maintaining uniform extension of the pleats and a spacer means is required which will be effective to maintain uniform pleat extension in horizontally hung shades as well as vertically hung shades.
Another problem with existing spacers is that, when the shade is closed, the spacer collapses into one or more loops extending from the rear or side of the shade. Since the spacers are frequently relatively long, up to several feet, these loops can also be relatively long, and may be aesthetically unacceptable in some applications. Further, if the rear projecting loops are too long, they may come in contact with the window or other opening being covered, or may rub on the floor for horizontally hung shades, interfering with the operation of the shade. A need therefore exists for a spacer which is designed such that the extent to which it projects from any side of the shade when the shade is closed is limited so as not to be either aesthetically objectionable or to interfere with the operation of the shade.
Still another potential problem with existing spacers is that at least portions of the spacer itself or a shadow of the spacer may be visible from the front of the shade when the shade is open. In some applications, this may be aesthetically objectionable.
While spacers of the type described above are particularly useful in connection with pleated shades, similar problems may arise in other types of shades such as weeping roman shades, where moveable ribs support loops of fabric therebetween and it is desired that the spacing between ribs be substantially uniform to provide uniform fabric draping. Similar problems requiring the use of spacers also arise in other types of shades or other coverings.